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Follow the reluctant adventures in the life of a Welsh astrophysicist sent around the world for some reason, wherein I photograph potatoes and destroy galaxies in the name of science. And don't forget about my website, www.rhysy.net

Saturday, 28 March 2015

The Universe is the way it is because things happened the way they did. That doesn't sound particularly mystical to me.

Yet that is the essence of the anthropic principle. It's more usually stated in a manner that causes all kinds of horrid confusion :

"In astrophysics and cosmology, the anthropic principle (from Greek anthropos, meaning "human") is the philosophical consideration that observations of the physical Universe must be compatible with the conscious and sapient life that observes it." - Wikipedia.

Different people have radically different interpretations of what this means. As you'll have already gathered, I fall firmly into the camp which says, "this is trivial, but sometimes useful". In this viewpoint, there is no "reason" that the Universe has physical properties compatible with life. It just does, and so we're here observing it. If things had been any different, we would not be here. Possibly some other lifeform would be around instead, or possibly not, it doesn't really matter.

The reason the anthropic principle is sometimes useful is best explained using maths - very simple maths, don't worry. Suppose I tell you to work out what x is if 5x = 10. Well, that's easy, x = 2. You solved that equation because there was just one unknown variable.

This also works for what seem like more complicated equations :

5x + sin(p) - cos(q) + (r*r*r) + (z*z*z) = 10

If I tell you that p =90 and q =0 and r =176 and z = -176 , it's now simple to work out x (it's two again). This time there were lots of other quantities involved, but since you knew what they all were it was easy to find the unknown variable x.

Anthropic reasoning is a lot like this. It says that since we know life exists, the properties of the Universe have to be compatible with that. So if we know enough about the properties of the Universe, we can work out values we don't know by assuming that they have to be compatible with the existence of life. In many ways, this is incredibly trivial : the Sun didn't explode yesterday, so stars can't be prone to exploding. We didn't get hit by a giant asteroid, so giant asteroids can't be common. And I didn't get eaten by a bear, so bears are rare in Prague.

Sometimes, anthropic reasoning can tell us more profound, non-trivial truths. The best-known example of this was the discovery of an energy level in the carbon atom by the great, controversial astronomer Fred Hoyle. The legend goes that he worked this out in order to solve how carbon is formed in nuclear fusion inside giant stars. He knew carbon existed - because he was made of quite a lot of it - but the only way he could get fusion to produce carbon was if the carbon atom had a very particular energy level.

Let's assume for a moment that that story is exactly true. It scarcely matters that Hoyle was partly made of carbon; it doesn't matter that carbon exists inside Hoyle or inside a wombat, the important point is that carbon exists at all. Moreover, he could equally have done this for another element less important for life. Or, as is very eloquently expressed in The Science of Discworld IV :"The Anthropic Principle only seems different from the Sulphuric Principle (a universe containing sulphur has to be suitable for making sulphur) because it's about us rather than a lump of yellow rock. But the Copernican Principle cautions us not to imagine that there's anything special about us, and in this case, there isn't. We are just one piece of evidence. An equally convincing case can be made that the Universe is uniquely fine tuned to make sulphur."

Even if you do think we humans are special, the point is clear. We could use anything else as the basis for an anthropic-like principle : monkeys, turkeys, bananas, Justin Beiber, rocks, bum fluff, Sarah Michelle Gellar, candy floss, clouds, lithium, chocolate, volcanoes, sand... whatever you like.

I already promised not to show Justin Beiber and if you really want pictures of bum fluff then you've come to the wrong place.

I'll die before I believe in the Beiber Principle, could easily be persuaded in the Gellar Principle, and won't ever stop believing that the purpose of the Universe is chocolate. And I'll actively go around trying to convince people of the Gellar-Chocolate principle. Mmm. Sorry, what was I saying ?

That we are sentient, or even alive, is hardly relevant for anthropic reasoning. The essence of it is that the Universe has to have the correct conditions to contain the things we observe within it - that it happens to include life is just the way it is. That we can sometimes work out other facts about reality from the existence of life doesn't mean that life is special any more than it means sulphur is special.

Why does this cause difficulties ?

The alternative, more extreme view is the so-called "strong" anthropic principle - bluntly stated, the idea that the Universe isn't just suitable for life, but designed for it - it has a purpose, as I alluded to with the chocolate example. This rests on the notion that the properties of the Universe have to be almost exactlywhat they are, otherwise life would be impossible.

Of course, we could invoke the Strong Sulphuric Principle to see how absurd this potentially is : a Universe containing sulphur doesn't necessarily have to have been designed to contain sulphur, any more than a house containing termites was designed to contain termites. Yes, the house was designed, but assuming some particular random feature of it was the purpose of the house is a very silly mistake.

Or, as in SODIV again :

"Why us ? The Strong Anthropic Principle just assumes it's obvious that we are the purpose of the whole thing. Sulphur ? Don't be silly."

An even better example might be a pile of sand that happens to have a stick on it. The pile of sand wasn't "designed" at all, let alone designed for the stick. The mere fact that things exist doesn't tell you they were designed. It doesn't necessarily tell you that they weren't designed either; the one implies nothing about the other.

But what about fine tuning ? Clearly a pile of sand is not at all fine-tuned, or optimised, to contain a stick. A house is fairly suitable for termites, but it's not ideal unless the entire house is made of wood. In contrast, the argument for the strong anthropic principle for the Universe is that the properties for life are so incredibly specific that it's like balancing a pea on a knife edge - move it even the smallest amount and it will fall. The Universe, it says, is not just suitable but optimal for producing life. And that's much more interesting.

If the Universe required incredibly specific conditions for sulphur to exist, and changing those conditions in any way would cause there to be much less sulphur, then the strong sulphuric principle might be valid. But if changing those conditions also changed a whole bunch of other things, we'd have to be very careful that we were sure sulphur was really the purpose of the Universe. That's why we ought to have a damn good reason for assuming that we're special - our mere existence and sentience doesn't automatically make us any more important (to the rest of the Universe) than non-sentient objects like rocks and Justin Beiber.

Indeed, one of the most profound discoveries from astronomy is the sheer size of the Universe. We know of only one tiny, pathetic scrap of rock where life like ours can exist. We're special because we're rare, but we're also totally unimportant for exactly the same reason. We matter to each other; the Universe doesn't give a damn.

The problem with the fine-tuning argument, as SODIV point out, is that the Universe is bloody complicated - as are the conditions for life. Change one parameter and you can compensate by changing the others. SODIV present the very nice analogy of a car :

"If you take a car, and change any single aspect even a little bit, the odds are that the car will no longer work. Change the size of the nuts just a little, and they don't fit the bolts and the car falls apart. Change the fuel just a little, and the engine doesn't fire and the car doesn't start. But this does not mean that only one size of nut or bolt is possible in a working car, or only one type of fuel. It tells us that when you change one feature, it has knock-on effects on the others, and those must also change."

Conditions for life aren't balanced on a knife-edge at all : actually, there's a huge plateau containing different combinations of parameters that would give a Universe eminently suitable for life. For example, if the Sun was a little cooler, Earth would be frozen - unless it was also a little closer to the Sun. And smaller, cooler stars live longer than large hot ones, so this might even be better for life in the long run. Similar argument can be made about the particular values of the fundamental constants. So there's not really much indication that ours is the Universe most suitable for life.

Take the carbon example. The energy level did turn out to be close to the predicted value, but you could actually shift that value by around 4% and still get about as much carbon produced as we see. A 4% error isn't precision engineering, it's a wonky stool. In fact you could actually get even more carbon if the energy level was a bit lower.

And then, just for good measure, there's evidence that Hoyle never even used anthropic reasoning and the whole story is a later invention. As I said, the important thing was only that carbon existed, not that Hoyle existed. He could have used an anthropic argument, but a "carbonthropic" principle would have been every bit as valid.

For even more examples of how fine-tuning is a myth, have a look at the Monkey God web program that lets you generate Universes and see how suitable they are for life. And have a read of the author's website too. And of course SODIV's chapter 22 is masterful, even if their discussion on atheism was just plain wrong.

In short, the Universe will always appear to be fine-tuned to contain whatever it happens to contain. Whether that includes life or not is just a detail.

Conclusion

The Earth and the Universe it resides in aren't some wonderful eden. The natural world is, by the standards of human morality, manifestly cruel and unpleasant. Natural selection is a ruthlessly competitive process : you win or you die, or more accurately, you win and you die. Supervolcanoes and asteroid impacts are periodically devastating for the ecosystem - countless species have gone extinct because they were unable to adapt. Life survives in spite of its environment as much as because of it. Arguments that the Universe is uniquely fine-tuned for sentient life don't have much force in the face of tsunamis, earthquakes and hurricanes.

Yes, this is obviously an example of how suitable the Earth is for sentient life.

Of course, you could still say that maybe the Universe isn't optimised for life, but it's still the best Universe possible for life to exist in. That's difficult to believe given the huge range of scope available given the number of parameters. More seriously, these arguments are almost always used to invoke the existence of a designer - in which case you ought to explain not why the Universe is so perfect for life, but why it is so clearly imperfect. At which point the arguments are revealed not necessarily as being wrong, but simply unscientific.

Moreover, you don't know what the designer's purpose is. You could very well say, "Sarah Michelle Gellar is so lovely that the Universe must be setup to ensure she exists." But you could equally say, "Justin Beiber is such a complete pillock that the Universe must be setup to ensure he exists"* - or even, "tsunamis are so awful that the Universe is setup to ensure they happen". The Universe is full of wonders and horrors, so there's nothing to say if the the designer was good, evil, or just a complete berk.

* Fun experiment to try yourself : use the anthropic principle for cheesy chat-up lines and scathing insults. As in, "You're so fine / such a douchebag (delete as appropriate) there's no WAY you're an accident !"

The Universe has properties which are sufficient for life to exist, but that's all we can say for certain. There's little to suggest the Universe is the ideal one for life to survive in, let alone that it was designed for a species inhabiting far, far less than 0.00000000001% of its volume. Virtually all of the Universe is completely unaware of our existence and most of it is an environment that would kill us in seconds. That's a pretty odd bespoke Universe if it's supposed to exist for our benefit, if you ask me.

Used to infer properties of the Universe based on other values, anthropic reasoning is perfectly sound. I would even say it's a very basic scientific idea : if I know some things, I can work out others. But using it to infer a design is ridiculous - of course we live in a Solar System where the planets are in stable orbits, of course we live on a planet with liquid water. The other planets in our Solar System are positively hellish for life as we know it : if there was one just star in all the Universe and the Earth its only planet, then there might be a good reason to suppose that the Universe was designed. But in reality the overwhelming majority of the volume of the Universe is dark, cold and incredibly lonely. That we exist somewhere which is light, warm, and not overtly hostile 100% of the time isn't coincidence, or spooky, it's necessary.

Or to put it another way, saying, "isn't it remarkable how perfect conditions for life are here ?" is as silly as saying, "isn't it remarkable that we live on a rock that's suitable for us to live on, instead of out in that immense cold void where we'd be dead in seconds ?".

The fact that an oasis (at least one) exists where we can survive, given the immensity of the Universe and the huge range of environments, is not in the least bit surprising. The Universe is the way it is because things happened they way they did. Being surprised at this is equivalent to being surprised at the existence of rocks.

None of this makes the Universe the slightest bit less wonderful. Whether you think the Universe is magnificent or oppressive, cruel or beautiful, sacred or profane, is entirely up to you.

Friday, 20 March 2015

If you've just wandered in off the street and have no idea what I'm talking about, here's the short version. Some time back, this gif and video were doing the rounds on the internet. Like a bad penny, they still keep turning up from time to time, with an astonishing capacity to go viral almost whenever they appear.

What Plait (quite correctly) describes is that the model of the Solar System this video promotes is utter nonsense. What I (also quite correctly) pointed out is that yes, the model is wrong, but the planets trace out helical paths through space even so. I even made a (much crappier) version of the gif to illustrate this. I gave the planets the correct 60 degree tilt relative to the direction of motion (which makes barely any difference at all) and put them in the correct order, just for the hell of it.

I've always maintained that it's that aspect of the video (showing our motion through space) that assures its popularity, rather than the alternative (wholly wrong) model it tried to promote. I did, of course, get extremely annoyed by the promotion of this nonsensical alternative model, but I wanted to make it absolutely clear that this helical-path business is perfectly correct.

I'm extremely pleased to tell you that I've just had a delightful conversation with DJSadhu, creator of the original video. I'll admit to a great deal of trepidation about even opening the email. After all, I wasn't particular polite in the original article, and I was fully expecting yet another angry email from a pseudoscientific nutcase. I get such things frequently enough that I strongly considered just deleting the email without even reading it.

Well, let me say this in no uncertain terms : I was wrong. Sadhu has listened to the critics and made a new video. Gone are the claims that the heliocentric model is wrong. Gone are the links to any alternative model of the Solar System created by someone who doesn't believe CFCs are the cause of the ozone hole. And gone are the links to the Fibonacci sequence as a fingerprint of God. What remains are some very nice graphics and a catchy soundtrack. The whole thing looks really well done to me.

When I watched it, I don't mind admitting that I was very pleasantly surprised indeed. I really can't find any show-stoppers with this at all. Really, if there are any inaccuracies in this one, I think this would be nit-picking.

As I pointed out in the first article, I couldn't see any hint of the Sun moving ahead of the planets, despite Phil Plait's claims (but keep reading) which would have been horrendous. Sadhu explicitly confirmed that to me :

"Again, the sun is not leading here, still not convinced it does. Although Bhat's paper put me on the "helical track", I do not take his "cone shaped model" as absolute fact... I've had of discussions with viewers, noobs, trolls, haters, lovers, and scientists, and I kind of doubt the cone shape model to put it mildly."
Seriously, what more can one ask for ? He freely admitted that his second video does show this Sun-leading model, but here he couldn't be any more clear : he's not trying to show that with this video.

Sadhu asked :

"And how come, even though the standard model is 'correct' and 'complete'... you had to come up with a completely new animation to show the old model is okay ?Because there was no such video... and that's what I find annoying."Science" quickly jumps onto the "it's all wrong" bandwagon... and then you have to go and tinker to personally make the first "correct" version (oh the angle is a bit different)The complete model should have been out there all along!!!! Noo, let's debunk DjSadhu, and then make the correct version - for the first time !"
I can see his point. There certainly wasn't a standard-model video out there - at least, certainly not one that's anything like as pretty or as popular. It would definitely seem very unfair to debunk the person who made such a successful video demonstrating (pretty much for the first time) the motion of the Solar System through space.

My response was to explain in some long-winded detail why the the standard-model video didn't previously exist, and what it was about the original that had got some people (myself very much included) riled up. I'll try and keep things a bit briefer here.

First, why there wasn't a video already. Any object moving on a circular path that's simultaneously moving forward must trace out a helical path. This ought to be incredibly obvious, but here's a simple demonstration you can try at home, provided you have at least one functional finger.

Hold your hand out and point one finger to the left. Now move your finger in a circle, and move your hand to the left. You'll see your finger traces out a helical path. There's nothing the slightest bit mysterious or profound about it - it's simple, basic geometry. No-one ever felt the need to make a video claiming "your finger is a vortex !"... err, well, on second thought maybe they did, but I'm not into that sort of thing, thank you very much.

Next. repeat the experiment but this time move your head at the same speed as your finger. The helices disappear ! Your head is now in the same "reference frame" as your finger - that's the heliocentric model, the standard diagrams of the Solar System you're probably familiar with. The heliocentric model is neither wrong nor incomplete, it's simply a choice of reference frame. And at this point, to demonstrate the fact that we've been aware of the motion of the Solar System for some time, here's the Galaxy Song again. Yes, I used this last time... but come on, it's a very good song.

However, while it may be completely obvious to me that the Solar System moves like this, it clearly isn't obvious to a lot of people. So I have to concede - empirical evidence demands it - that Sadhu's video (notwithstanding the alternative model, which we'll get back to shortly) is beneficial in that it does a good job of illustrating this fact.

The second point - it wasn't the video that got me riled up, it was what it was promoting. My response (shortened slightly) was as follows :

"First, you presented the idea of helical paths as though it were some revolutionary new model. You could have very easily checked with more or less any astronomer who would have told you that we already know this is the case.

Second, I completely agree with Plait about Bhat - I think he's nuts. His document put me in mind of Moon landing conspiracy theorists and Hollow Earth believers.... Your claim was not, "hey everyone, in this reference frame we're moving on a helical path !" (which would have had people saying, "pretty neat !") but instead, "hey, this totally ludicrous model claims we're moving on a helical path, so I've overturned heliocentricism" (which has people thinking you're mad).

Third, you seemed to be strongly implying that you didn't believe the 60 degree tilt of the ecliptic was even possible, because you thought it would mean that sometimes the planets are moving faster than the Sun. Plait's analogy of swinging a ball on a string while walking down the street is correct - this poses no problem whatsoever for classical mechanics.

Fourth, you were claiming that in the classical model the planets should be eclipsed by the Sun once per year. This does not happen, simply because the orbits aren't all perfectly in the same plane. An alternative model is not necessary to explain this.

Fifth, I don't think it's fair to say that discrediting the other stuff on your website was not relevant. You made quite an explicit link between the motion of the planets and DNA and other organic structures. In effect, you claimed that your alternative source model provides evidence for a pseudoscientific idea about the Fibonacci sequence. That was never going to go down well."

Sadhu's response was pretty much everything I could have hoped for. I've re-arranged his response a little, for reasons that will become apparent soon enough. It deserves to be quoted at length.

"About two years ago I heard of this "Bhat model", the cone shaped, helical solar system. It fired up my enthusiasm and I started making these videos. Frankly I was a bit pissed about the 'standard model' (as you can tell by the claims in the first video), because it just did not show properly how things work. For me personally, the difference between a stationary looking dinner plate model and this dynamic, spiralling model was huge. So I made the videos, the first one (solar system) just showed this helical model, and the second one (our galaxy) showed this cone shape and the helical pathway of the sun, and lots of other debatable details. Especially that second video was reason for most resistance and criticism from the scientific community, but it affected how both videos were regarded.Anyway, that was how it worked back then. Now, two years later, I'm certain of one thing: the huge difference between the stationary looking dinner plate model and the helical model remains.As long as I leave out the wacky stuff, the cone shaped stuff, leave Bhat out, do not argue about the shape of the sun's path, it could easily be accepted.So that is kind of what I decided, I want to make this "Solar System 2.0" video, with no outrageous claims, none of the disputable stuff, just the best representation of the helical model that I can make. And make it art.The video does not claim that the heliocentric model is 'wrong', it puts it into perspective. For most people a new one. Also, the cone shaped stuff is not in the video, not important, and should certainly not ruin the message.I'm not after words, but after images. So I left the words out. Vortex/helix, wrong/incomplete, all those terms are vulnerable ingredients in a video, and they are not the point !The point is how people 'see' the solar system. Although the helical paths may have been known to astronomers and astrophysicists (and part of the public), what people 'see' when they think about the solar system is in my opinion incomplete."
It would be pretty damn tough for me to disagree with any of that. In fact, let me state it more explicitly : bravo, Sadhu, I salute you.

He did, however, make two statements I dispute - one is pretty minor, the other major but not as bad as you may at first think.

The minor point : "The only bold move I made was to 'blame' the upward angle in the sun's path for the difference between 90 and 60 degrees. "

I'd say the fact that the planets don't move at 90 degrees to the direction of motion is simply chance - they could be oriented at any angle. A more interesting, related point that someone mentioned to me elsewhere is that there's no reason the plane of the ecliptic (the narrow "sheet" in which the planets orbit the Sun) should always be at the same angle relative to the direction of the Sun's motion around the center of the galaxy.

That's a little bit complicated a statement, so probably an illustration will help. Here's what you might interpret Sadhu's video as showing (he confirmed to me that this is not what he's trying to show, however) :

Here the Sun (yellow circle) and the orbits of the planets (white lines) are shown at different points in their orbit around the galaxy (obviously they're not to scale). If they orbited like this, the paths of the planets would always trace out neat helical paths.

That might not be the case though. The plane of the ecliptic could keep the same angle throughout its orbit around the Galaxy.

In this case, the neat helical paths would only result at two points in the orbit (those at the extreme left and right in the above image). The result of the time there'd still be helices, but they'd be distorted.

At the other extremes (the top and bottom in the image), the planets would trace out something more like a flat, spirograph pattern than a 3D helix :

Which is correct ? Actually, I don't know. Or even care very much - and that's where Sadhu and I have a more profound disagreement. For me, the motion of the Solar System through space is neither very interesting scientifically nor philosophically*. For Sadhu, however, things are different :

"Yes, in my personal experience the helical paths, DNA, life, Universe is all connected. Hell, I would not be surprised if one day the discovery is made that the entire Universe is conscious."
Sadhu and I are never going to agree on that. And you know what ? That's absolutely fine. I have stated severaltimes previously that I have no problem with people holding irrational beliefs, I don't see them as inherently wrong or amoral. What Sadhu is doing here is making a very clear distinction between his unscientific opinions and objective facts. That is commendable. If more people could do this, the world would be a happier place.

Conclusion
I still stand by my original article. I don't think I was wrong to debunk the claims against heliocentricism at all. As I said, the problems with the original video were minor, but what it was promoting deserved to be shot down.

Sadhu is no longer using his talents to promote anything remotely unscientific. True, he does still have unscientific opinions (and a brief glance at his website shows him to be interested in things I profoundly disagree with). Some of what he says is "disputed" I would say "no, that's just wrong" - but come on, there's no point being a jerk about it. For me to fail to publically acknowledge the virtues of this video, would, I think, make me a complete arsehole.

People, this should be seen as a win-win scenario. The essence of Sadhu's original video was correct, and he's publically declaring skepticism for the second one. His new effort has none of the quackery associated with the first. To me, that seems like the best of all possible outcomes. Demonising your opponents is no way to win them over - and sometimes, it turns out they were saying something valuable all along.

Star Trek's answer was a clear "no" - even the differences between
different species are not relevant.

That latter question may seem strange. Clearly, in one sense it obviously does matter, because there is racial conflict. If race is not a real, biological difference, then surely that's all the more reason why racism is not only an evil thing, but a stupid and even more unjustified one as well. This is true, but also, perhaps, utterly irrelevant.

An alien visiting Earth for the first time might indeed conclude that there are different races. Certainly, people in Asia tend to look different from those in Africa or America. But then, within each group there are massive variations, and the differences between the groups are relatively subtle. More importantly, would the alien conclude that the differences between the different races are anything more than superficial - is there anything to suggest that one race is more intelligent than another ?

In principle, this could be the case. After all, different species undoubtedly show different innate abilities. So, since we look slightly different from one another, perhaps the differences are more than skin deep. But equally, the reverse is also true : there's no particular reason to assume that the differences are anything more profound than hair or eye colour or toenail growth rate or nostril hair content or any of the million other small differences between individuals. They may very well tell you absolutely nothing about intellect.

If you ever need reminding just how great the differences between individuals of the same "race" can be, look no further than Eric Pickles and Scarlett Johansson - and then try telling me that skin colour or eye shape is some sort of important racial feature.

Let's assume for the sake of it that different races do exist and that some of them are more intelligent than others. Even in that absurdly unlikely case, racism would still be wrong. Assuming that because one more person is incapable of something because of what they look like is to ignore objective standardised testing and say "hell with it, even if you are an exception, I just don't care." It's exactly the same reason that laws discriminating against women don't make sense : if they can do a job to the same standard as a man*, then let them.

* I'm thinking here specifically of the armed forces, where the argument has been made that women aren't physically strong enough. This is daft. Simply make the strength requirement the same for men and women. I don't care if this excludes the majority of women : I care that women aren't automatically excluded, but are given the same chance as anyone else on the basis of merit.

This of course is an extreme and totally hypothetical scenario. In reality, whether races exist or not is a far more complicated question (see the links at the start of the post). However, that there aren't any intrinsic differences in intelligence or ability is now so well established I feel zero need to discuss them any further. And it's that fact which makes the question of whether races exist largely irrelevant - if they do, they certainly do not imply any predisposition towards different abilities, and individual variations completely overwhelm any racial bias.

But even if races do exist - and I'm not geneticist nor an anthropologist, so I can't tell you if they do or not - it's interesting to consider what people define as race. The Scots aren't generally considered to be a different race to, say, the English or the Welsh, even though they're considered to be different "peoples", whatever that means, and there are even visible differences in appearance.

Regardless of whether races exist or not, how we define racism is of vital importance - even, perhaps especially, if race is purely a social construct. Everyone (sane) would accept that discriminating against someone on the basis of skin colour is racist. Hair colour, however, which is genetically determined, is simply not considered to be a defining racial feature*. And that alone tells you something about the absurdly subjective notion of race - regardless of whether it really exists genetically or not, the definitions society adopts are entirely arbitrary and totally unjustifiable. Society's notion of race is just plain ridiculous - even if race itself is somehow real, which it might very well not be, society's idea about it bears little or no resemblance to reality.

* Though it was once, of course, with astonishingly disastrous results. Which only further demonstrates that since our ideas of race change, they are highly subjective.

INTERVIEWER : So, in UKIP land, would there be a law against discrimination on the grounds of race or colour ?FARAGE : No ! Well, you know, we are colour blind. We as a party are colour blind. INTERVIEWER : We have these laws for a reason, you know. Before we had these laws, people were discriminated in favour of their... families. And that led to, by the way, incompetence. Never mind the fairness question - people were employing people who couldn't do the job, just 'cause they looked like the employer.FARAGE : If we'd sat here, 40 years ago, having this conversation, your point would probably have been valid. I don't think it is today. I really don't think it is today.

What. The. Frak.

Jesus H. Christ people. Removing this law because it's "irrelevant" ? Don't make me laugh. Even if I accepted that there is now so little racism in Britain that it's not relevant - and I don't - removing it sends a signal so clear that our hypothetical alien observers could easily see it from space. It's tough to imagine a more blatantly, manifestly racist policy.

Removing a law which says, "don't discriminate on the basis of colour" is identical to saying, "it's OK to discriminate on the basis of colour". They are one and the same. It is absolutely astonishing to me that people cannot grasp this incredibly simple fact. Nigel, until this point I've been willing to concede that perhaps you yourself aren't racist, despite the fact that many in your party clear are. But I can't give you any more benefit of the doubt - this policy is objectively racist, even by the absurd standards by which society defines race. You may as well be holding up a big sign that says, "We're a big bunch of racists !".

Farage has said that his remarks were "wilfully misinterpreted" - which is clearly not true since the question was clear and unambiguous, as was his answer. Slightly more interestingly, he also said that he was talking about "nationality, not race." I'll return to that shortly.

One may legitimately wonder, perhaps, why when Gordon Brown proposed "British jobs for British workers", no-one proclaimed him as a racist, yet when Farage says much the same thing, people do assume he's being racist. Well, the above proposal to remove race discrimination laws pretty much answers that - it's the strongest manifestation yet of a series of rather unpleasant proposals that smack of racism, even if they aren't all so blatantly racist themselves. Brown never gave any hint that he found foreigners somehow distasteful; Farge does this as a matter of course. Context matters.

The idea that he was talking about "nationality, not race", is a bit more interesting. First, just to re-iterate, he wasn't - because those laws are specifically about race. There's what the question was unambiguously about. Secondly, as we've seen, society's definition of race is totally subjective. That means disentangling race and nationality is a very messy business - you can't assume that one implies the other, but equally, you can't automatically assume that it doesn't.

What about UKIP's idea to allow employers to favour British employees, then ? The argument has been made that this is not necessarily racist because the British themselves are a diverse bunch of races. That's true as far as it goes. But it misses the fundamental point : laws which favour one nation over another are xenophobic - and xenophobia is the handmaiden of racism*. Any law which says, "you're from another country, you are not entitled to the same rights as other people living here" is intrinsically xenophobic.

* Worst. Handmaiden. EVER.

That doesn't necessarily prohibit immigration controls, mind you, even very strong ones*. Even an absolute limit on the number of migrants allowed to settle per year isn't intrinsically xenophobic, provided it doesn't discriminate on the basis of country of origin. It's simple really : you do it on the basis of qualifications and/or whether prospective immigrants have found employment or not. Once you let them in, however, you have to treat everyone equally. That someone is from France and not Ghana doesn't mean you can treat them differently because "they're French, they're the same race so that's OK I'm not being racist by denying them basic rights".

* But migration is good for Britain. Studies have shown this time and time again : people are coming here to work, not for benefits. The idea of benefit tourism is a pure, scapegoating myth with little or no basis in fact.

Discrimination based on the country of origin may or may not be racist in the strictest sense. If race does exist genetically, then it may not be racist. If it doesn't, which seems likely, then it's absolutely the same as racism because in that case race is purely an artificial, social construct. But in either event, this misses the bigger, infinitely more important point : it's still discrimination. I don't really care what else you call it. It's still wrong.

It ought to be simple to have a debate about immigration without being racist : talk in terms of population numbers, for example. It's entirely a legitimate concern as to whether the UK has the resources to sustain a much larger population. But that's got absolutely frickin' nothing to do with the ethnic composition of that population or where they come from. That, by pointing fingers at specific groups of foreigners, is something Farge is fully at fault for.

Farage keeps saying things like having a "sensible, grown-up debate". Then he does things like implying that Romanians are criminals and saying that people should be allowed to be racist. Cameron keeps saying that we should discriminate on the basis of wealth, for crying out loud. That somehow a county's economic status has any bearing on the intelligence of its citizens.

I'm writing this from the Czech Republic, where the average salary is about half to one-third that of the UK. I work with people far more intelligent and qualified than me on a daily basis. I've taught numerous Puerto Rican students, a location which would, if it were an American state, be by far the poorest, and they were at least as competent as those in the UK. This whole idea of "wealthism" is a nonsense.

Cameron (standing, second from left) at least knows at lot about money, so I guess that makes him qualified to pronounce judgement on poor people.

There's only one right way to discriminate : merit. That can mean many things, from whether someone has the right skill set to do a job, which you can objectively test for, to the right cultural values to integrate into society - which is of course very much harder to quantify*. I believe in multiculturalism, but there are legitimate concerns over the extreme cases such as "honour" killings and religious extremism. I would be hypocritical if I said we shouldn't debate religion - but religion is an ideological set of beliefs and values, not a fundamentally irrelevant physical property of a person like their nose hair content or natural hair colour. It's far more directly relevant to whether we should grant a person access to our country or not than which country they're from.

* Recurring ideas to teach "British values" directly may be flawed and unworkable, but they're a damn sight better than allowing employers to favour British people over foreigners.

And let's not kid ourselves - the British people are just as capable of atrocities as those of other cultures too. No matter how tightly we manage immigration, it won't stop horrible things from happening. Rather, I think, the reverse is true. There's a danger that when you strongly oppose something, you become the very thing you oppose. Hating intolerance often leads to a hateful intolerance. When we debate extremism - be it cultural or religious - we must tread very carefully.

But that's not to say we shouldn't debate at all. We should - and it won't be easy. Debating how far we should extend toleration is a tricky subject, but there's no need for such a debate to involve race or nationality. If you want to debate immigration, make it about the values of the people you propose to allow in or out, and how we integrate them into society. But neither their ethnic origin not their country of birth have any more relevance than their nostril hair content.

Conclusion
People who have the audacity to suggest that "racist bigoted lies" are being told about UKIP need to have their heads examined. The reason UKIP are often perceived as racist is because they themselves make the debate about race when it needn't be. They also turn more or less every issue into one about immigration and the immigrants. This approach says, "No, we don't need to improve ourselves or our own systems of governance, we just need to stop these people from coming over here and ruining everything."

Making immigrants into scapegoats avoids having to deal with the real issues like austerity, education, and health. That's the bigger problem with UKIP - diverting attention from the serious problems of our own making by blaming someone else.

I do not think immigration is the fundamental problem we should be prioritising right now. I think it's generally an asset, not a burden. I've benefited directly from the E.U.'s freedom of movement laws myself. Sure, benefit tourism isn't a good thing - but the evidence says that that's not really happening. By all means, put regulations in place to stop it. But UKIP's idea that we should get out of the E.U. and, far worse, simply throw away all that progress on preventing racial discrimination... well, yeah, those things are racist, actually.

The word "racism" may be used too often, or it may not. It doesn't really matter, because society's use of the word is pretty much entirely arbitrary. It may even be a wholly arbitrary concept. The point, however, is that discrimination on the basis of where someone is from is wrong. Arguing about the meaning of "race" won't change that simple, basic fact.

EDIT : Appendix

The topic of positive discrimination was raised in discussion. Since the interviewer's question was about negative discrimination, this is only tangential to the main subject. But it's quite interesting, and worth a brief postscript.

A law prohibiting negative discrimination is not the same as one that encourages or mandates positive discrimination (a.k.a. affirmative action). Saying, "don't discount this person from employment because of their race" is categorically different to saying, "hire more people of this ethnicity". Now since the interviewer's question was about "a law against discrimination on the grounds of race", Farage was unequivocally suggesting that laws preventing negative discrimination be scrapped - a very different, far worse prospect than suggesting affirmative action be stopped or reduced.

Positive discrimination is in principle just as bad as negative discrimination, because it basically is negative discrimination in a cunning disguise. Saying, "give priority to this person because of their race" inevitably means that those of a different race lose out. If you hire someone because you need to employ a certain percentage of people from a specific group, that is hardly likely to lead to a meritocracy.

But context matters. Such an approach recognises that employers have chronic problems where they exclude those of a particular race, religion or gender - sometimes not even on a conscious level. In those cases - especially where the employment rate of women and minorities is close to zero - I believe that taking a more heavy-handed approach is the only way to make progress. If you don't start enforcing an intake of minorities, none will ever get hired - regardless of whether they have the abilities required or not. Generally speaking, an organisation which implies no women far more likely indicates sexism than a difference in gender skills. Sometimes, you've got to take a sledgehammer to people's attitudes - it's the only way they'll change.

Monday, 9 March 2015

Some time ago I made a short video, The Hydrogen Sky. It's basically about the hydrogen content of our galaxy and the ways we visualise the data. Which is nice and all, but wasn't exactly what I was aiming for.

In this post I want to redress the balance. This one's going to be more about science; if you're interested in data visualisation, see this detailed earlier post. In this one I want to take the term "hydrogen sky" - a title I picked last time largely because it sounded neat and I'd already used "hydrogen universe" - more literally.

For the ultra-simplified version, which has pretty pictures and almost nothing else, see my website.

Hydrogen, FTW !

The space between the stars is not empty. The so-called "hard vacuum" of space only means that the density of material there is very, very low. Seriously low. With something like 1 atom in every cubic centimetre, it's roughly a hundred thousand times less dense than the best "vacuum" ever created on Earth in a laboratory - and unimaginably thinner than normal air. The number of air molecules in a cubic centimetre of the air you're breathing right now is something like 30,000,000,000,000,000,000 (thirty quintillion - yes, apparently "quintillion" is perfectly legitimate).

So, not empty. Just incredibly, absurdly, outrageously, disturbingly thin, like Megan Fox. Unlike Megan Fox, who is confined to a few crappy movies, this gas pervades all of space*. And as such, despite its incomprehensible thinness, it's absolutely spectacular - far more impressive than what's in visible light. As already shown in the most popular part of the original video :

Hydrogen data from the LAB survey (unfortunately no longer available for reasons unknown), processed by me.

* Well... all the space between the stars, at least - outside of galaxies, where the density of stars is much less, the density of the gas is also even less.Incidentally, if you're wondering about the space between the atoms, well they're not really empty either, but that's a whole other issue I don't want to go into.Our eyes can only receive light of a narrow wavelength range, from around 400 - 900 billionths of a metre. More incomprehensible numbers, sorry about that. But visible light is just one part of the electromagnetic spectrum - calling it just "light" is a bit misleading. There isn't anything fundamentally different about the microwaves you use to heat food (or send a phone call) and the light you see coming from the sun, except that microwaves have longer wavelengths. In fact, bees can see into the ultra-violet (light of a slightly shorter wavelength than we can see), while snakes and beetles can detect infra-red (a bit longer than "visible" light). So seeing other wavelengths is perfectly natural.

Atomic hydrogen gas emits at a wavelength of about 21cm - far longer than any animal can detect. Calling this emission "radio light" may sound strange, but it's totally valid, and gets away from the whole annoying, perpetual myth that radio astronomers like to "listen" to their data. With a few noteworthy exceptions*, listening to radio data is a daft as listening to a photograph - sure, you could spend ages developing some way to translate the data into sound, but why would you ? It's far simpler to just look at it. Ordinary home radio sets only generate sound because what they receive is artificial, and has been specially designed to make meaningful sounds when the radio processes the signal.

* One of the great pioneers of radio astronomy, the extraordinary Ruby Payne Scott, listened to the Sun using headphones, a la Jodie Foster. The Sun is exceptionally bright and changes rapidly, so with the relatively primitive radio equipment of the day, this made sense. Pulsar astronomers also sometimes generate sounds from their data, though this is generally only to impress the public rather than do actual science.

Of course, we radio astronomers pose like Jodie Foster at every opportunity.

Under the Hydrogen Sky

So, to map the hydrogen gas, we need a radio telescope. There are many good reasons why seeing radio instead of visible light doesn't occur naturally, not least of which is that the much longer wavelengths need bigger telescopes to see details as small as we can see in the optical. The above image was made using telescopes about 25 metres in diameter, and it can only see features as "small" as half a degree across - the size of the Moon as seen from Earth. It looks nice in the gif only because the field of view is so large - zoom in a bit and everything looks blobby (technical term). But if we could magically see both the radio and visible light, the sky would look a lot more interesting.

Old Town Square, Prague. Photo by me.

A few points about how this image was constructed (feel free to skip the rest of this section if you want, I don't mind). First, this image relies on much higher resolution data with a larger telescope. Second, the colours - they're false. They have to be, because you can't see radio light with your eyes. But the structures visible are absolutely real, as real as anything you see with your eyes. The colours are false but not meaningless - they represent how you might perceive the world if you were a walking radio telescope (human vision is complicated to say the least, but let's keep things as simple as possible).

Just like with visible light, radio waves don't come at a fixed wavelength. The red colours indicate hydrogen detected at longer wavelengths, the green slightly shorter, and blue the shortest of all. That's exactly how you perceive colours in visible light, it's just that here the wavelength range is very different.

Thirdly, the alignment of the images. If you came here after watching the YouTube video, you may have noticed the cautionary note that the images were aligned "as closely as possible". I have a model of the sky with a coordinate system that allows me, in effect, to position the camera anywhere on Earth and see what the hydrogen would look like from that location. The only problem is determining the exact location and orientation from a photograph. The thing is, it's very rare to have the exact latitude, longitude and orientation of the photograph, so some guesswork has to be used. Now for the above image I know where I was and which way I was looking, and the field of view of my camera. So I can say quite confidently that that is actually what the real hydrogen looks like, more or less, in that part of the sky.

The grid shows standard equatorial sky coordinates. The two lines protruding from the sphere are markers
to help me convert between equatorial and galactic coordinates. The optical image of the Milky Way, as
well as looking pretty, helped me to check that everything was lined up correctly.

Authenticity is important here. Not so much for which precise feature is visible from where - basically the sky would look awesome everywhere - but more getting the size of the features right in comparison to the landscape. But information is usually limited - not lacking entirely, just limited. So although I try to align everything correctly, don't go thinking that this is at all precise. It's a "best guestimate" - you'll see roughly the correct features in each location, of the approximately correct size.

I tried to use my own photographs wherever possible, but since I wanted to make the final video and image set as international as possible, this wasn't feasible in every case. For those places, I used Google Earth to try and figure out where the photographer was and what the field of view of the image is. Again, a best guess - certainly a lot better than not guessing at all.

In one case though, it was necessary to abandon the alignment altogether. A major limitation is the lack of high-resolution data for the whole sky. With a resolution of 0.6 degrees (just a bit bigger than the full Moon), LAB survey data covers the whole sky but doesn't look very impressive unless you have a very wide field of view. GALFA data from Arecibo is more than 10 times better, but only covers the 40 degree swathe of the sky that Arecibo can see (since the dish can't move). Unfortunately, some famous monuments aren't aligned in such a way that tourists have taken photos at an angle where the GALFA swathe would be visible. Rather than using the correct but blobby-looking LAB data, I cheated and used GALFA anyway.

You can think of this case as being representative of what you would see - the size of the features is still correct, you just wouldn't see those particular features in that location. That doesn't matter much for these images, since the hydrogen in our own galaxy looks very similar everywhere. It becomes a lot more important when we look further afield.

Somewhere in Snowdonia I visited in 2010. Image alignment here is a case of "whatever".

Choice of images - and therefore locations - to use was limited. Trees make life extremely tedious when removing the original sky in the image. Bright daylight is OK as long as the Sun is behind the camera so that shadows aren't obvious, but cloudy days are better. Not misty though, because a higher contrast makes it easier to trace the edges of the objects in the scene. And water is generally best avoided, unless it can be entirely replaced with CGI (as in the above examples), otherwise the lack of reflection of the sky looks dreadful.

In the video, in most cases I show the sky rotating - again, as close to reality as possible, just with a huge speed exaggeration (typically one rotation in 20 seconds instead of 24 hours).

Beyond the Sky

Your eye processes light in a very different way to a radio telescope. Roughly speaking, although your eye can detect what wavelength (or colour) the light is at any different point, if it receives lots of different colours, they all get squished together, in a sort of big... ball... of wibbly-wobbly, lighty-wighty.... stuff. Umm. The point is, you only see one image, and that's not what happens in a radio telescope.

A radio telescope makes a map of every different wavelength it can see. Imagine if you had the ability to, at will, only see objects of the colour red, or yellow, or beige. Urgh, no, not, not beige - green, perhaps. That's what a radio telescope does (at least when it's mapping hydrogen), except that it records hundreds or thousands of different wavelengths at the same time. Point your camera at something and it records a single image; point a radio telescope at something and it records hundreds of images.

What this means is that by changing which precise wavelengths we're looking at, we can get something like an auroral display. Essentially we're looking at hydrogen in different parts of the galaxy.

This particular shot was cut from the animation when I accidentally deleted it before I could render it at the correct resolution. Ooops.

The wavelengths in that sequence correspond to hydrogen in our own galaxy. Again, it's as real as anything you see with your eye. Now as I've written about previously, the different wavelengths tell us about how fast the gas is rotating, and we can use that to map the structure of the galaxy. But when we start to go to longer wavelengths, we eventually start to detect hydrogen from outside our own galaxy. Perhaps you've already seen the following famous image :

This is how the Andromeda galaxy would look if it was brighter - it really would be that large in the sky. But, just as the hydrogen in our own galaxy would look more impressive than the stars, so too would the hydrogen outside our galaxy. Andromeda itself would appear about twice as big again if we could see its hydrogen, but this would be absolutely overwhelmed by one stupendous feature : the Magellanic Stream.

One can't help but wonder how our history, our myths would have been different
under such a sky... well not really. I just thought that sounded good.

From the far north of the world, like Cardiff and Prague, the stream would be big, but to see it in its fully glory we have to go much further south. From Sydney, the stream appears as a gigantic ribbon of fire spanning about two-thirds of the sky - possibly more. No-one knows exactly how long it is - as observations get more sensitive, fainter parts of the stream keep being discovered. At present, it's reckoned to be something like 600,000 light years long (Andromeda is about 2,000,000 light years away). It is indisputably enormous by anyone's standards.

At the heart of the stream are two small fuzzy blobs, the Magellanic Clouds. These two small, unremarkable galaxies are entirely forgettable in visible light, but their hydrogen light tells us that something interesting is going on. Somehow - and the details are not well-understood - their gas has been stretched into this spectacular feature. They're a great example of how observing the hydrogen gas can tell us things we just couldn't guess by looking at the stars.

Imaginatively, they're called the Large and Small Magellanic Clouds.

Now you might wonder if these two boring little galaxies can produce a feature like this, what the hell happens when two of the bigger galaxies start dukin' it out ? Surely, if the Magellanic Stream is like two Japanese fighting fish picking bits off each other, then two giant galaxies colliding would be like King Kong vs Gozilla, right ?

Well, not so much. Although there are certainly galaxies which are ten, twenty, thirty times as massive as the Magellanic clouds, the longest known hydrogen streams aren't all that much longer than the Magellanic Stream. There aren't that many really long - say, more than 300,000 light years - hydrogen streams known, probably no more than a few dozen. At 2,600,000 light years long, the very largest currently known is this one, shown below, while a more famous example - the Leo Ring - is scarcely shorter at 2,500,000 light years (although that assumes the ring is complete, but no-one knows if that's the case).

The thing is, even though the galaxies involved are very much more massive than the Magellanic clouds, the other hydrogen streams found are no more than four or five times longer. Really long streams are rare. In some cases, galaxies don't contain as much hydrogen as we'd expect, but it's not at all obvious where that hydrogen has gone. It also seems that hydrogen survives galaxy mergers pretty much intact. That's especially weird - there's a correlation between hydrogen content and star formation rate, and we know there's lots of star formation going on in merging galaxies. And yet the effect on the hydrogen seems to be precisely diddly-squat.

Hydrogen is the simplest atom there is. Just one electron buzzing around one proton. That's all there is to it. And yet, after more than sixty years of observations, even this simple element continues to surprise us.

Tuesday, 3 March 2015

So, you've started learning Blender and obviously the first thing you want to do is model a squid. But there are sooo many buttons ! Which one to press first ? Unbelievably, there is no "add squid" button, but have no fear. With this helpful guide, in as little as nine years you too will be able to create your own virtual kraken to terrorise the briny deeps - in just 17 difficult steps !

I mean HOLY CRAP that is a lot of buttons.

1) Do a PhD in astronomy. Befriend someone who's really keen on galaxy simulations. It may seem like a odd beginning, but don't worry, it'll all make sense in step 10, probably.

2) Become vaguely confused about why there are lots of galaxies without much gas in the Virgo cluster, but no sign of where the gas has gone.

Well, not many. This one is a clear example of a galaxy losing gas in a long stream.
But while there are hundreds of galaxies in the cluster with less gas than expected, there
are only four with features like this.

3) Fly to a tropical island and use the world's largest telescope to do the most sensitive hydrogen observations ever undertaken of the Virgo cluster and look for gas streams. I mean, that ought to do it, right ? Wrong. Fail miserably to find any.

4) Write a program to increase sensitivity by averaging the data in four hundred million different areas. Because you're young and stupid, you have no idea the CFITSIO library exists and you don't know Python or IDL. This means you're going to have to use a lot of "call system commands" to mbspect. Like, a lot.

Still fail to detect any streams.

5) Boldly declare, "Well gosh darn it, I don't think there are any hydrogen streams in this area !". Argue with supervisor.

6) After three years, frantically complete PhD, then live in the jungle for two and a half years publishing papers. Tell everyone it's really important you find those streams. Keep your squid-making plans secret, for now. Oh, and spend six months learning to drive first, but fail the test four times. If possible, write a 3000-line Python script for Blender to load astronomical data files. Keep raving on about it to anyone who'll listen.

Remember, this is all in aid of modelling a squid ! Try to stay focused, will you ?

Along the way, get stuck in a hurricane, adopt cats, write terrible poetry, create strange glass cubes, learn IDL, fail to learn any Spanish, perpetually complain about the humidity and lack of public transport, bake everyone brownies and keep drinking plenty of tea and pina coladas.

7) Decide that the jungle lifestyle isn't for you and move to a major European city where the focus is on simulations. Keep working on that script for another year. Publish more papers.

9) Realise that the gravitational fields of the hundreds of galaxies buzzing through the cluster are probably going to make life quite difficult for any gas that does get removed from the galaxies.

Simulation showing the trajectories of 250 galaxies moving through a cluster.

10) Ask your friend (you didn't forget about him did you ?) if maybe his old galaxy harassment model would be suitable for making a squ... NO ! You must keep your squid project a secret. No-one's going to let you play with high-end simulations because you want a virtual squid.
Tell him it's about studying what happens to long streams of gas in a cluster environment. That ought to work.

11) Express delight when your friend returns the galaxy positions extracted from a big simulation that had full baryonic physics* included. This is pretty cutting-edge stuff and he's worked hard on this, so be polite. Humour him with clever banter about being interested in dramatic things like, "the fate of the stripped gas". He doesn't need to know about the squid... yet.

* It's not actually that simulation, but they have the best website.

12) Convert your friend's Fortran (urgh) script for generating streams into a nice Python version*, that can automatically place the streams in a variety of different places in the cluster. Then you can sit back and watch what happens when a stream gravitationally interacts with all the galaxies in the cluster. That should give you a decent chance of creating a squid.

* You did remember to learn Python, right ? If not, return to step 6.

13) Drink tea for a week while the simulations are running. Try and keep busy by watching award-winning BBC documentaries about squid.

14) Have a look at the results. Say "ooooh". Realise you have to grid the data into position-velocity cubes to make any meaningful comparisons to observations.

15) Momentarily despair because the simulations look more snakes than squids ! And who cares about crappy old snakes ? No-one, that's who.

16) Realise you can grid the data is a better way ! Throw away that lousy velocity axis and replace the cube with a series of integrated flux maps, centered on the mean particle position, with time as the third axis. Those nine years of Python scripting ought to make that a doddle. And behold !

17) Say, "hmm, yes, indeed that does look quite a lot like a squid". Ask colleagues if they think "Cthulhu" or "Squiddy McSquiddington" would be a better name. When they look at you like you are a crazy person, realise that they are correct. You've wasted nine years of your life. Take up golf instead.